Localization of Objects In Indoor Environments Using FMCW Sythetic Aperture Radar

Abstract

FMCW radars offer an interesting solution for object detection in a variety of environments due to their reliance on radar waves instead of on visual methods like cameras. Though FMCW radars are good at detecting if objects are present, they struggle with localizing objects on a heatmap. Instead, objects appear as wide blobs spanning 15◦+ degrees and objects placed closer than the minimum angle resolution cannot be independently separated. Synthetic Aperture Radar offers a solution to these issues. By moving the radar via fixed mechanical steps and coherently combining measurements with a backprojection algorithm, a large virtual array of antennas can be created. With a sufficiently large virtual array, resolution under 5◦ can be achieved with a theoretical minimum angle resolution of 0.8◦ being possible, representing a theoretical 19x improvement. Experimental results showed that two targets separated by 10◦ were distinguishable using SAR but were indistinguishable in a single snapshot. Experimental results validated a range resolution of 10cm, close to the theoretical minimum of 8.33cm.These results were able to be achieved using a TI IWR1642 Boost commercial off-the-shelf radar module.